scholarly journals Delineating reclamation zones for site-specific reclamation of saline-sodic soils in Dushak, Turkmenistan

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256355
Author(s):  
Elif Günal
Keyword(s):  
Soil Salinity ◽  
Land Development ◽  
Soil Salinization ◽  
Accurate Information ◽  
Soil Reaction ◽  
Target Area ◽  
Sodic Soils ◽  
Spatial Trend ◽  
Soil Layers ◽  
Best Management

Soil salinization is the widespread problem seriously affecting the agricultural sustainability and causing income losses in arid regions. The major objective of the study was to quantify and map the spatial variability of soil salinity and sodicity. Determining salinity and sodicity variability in different soil layers was the second objective. Finally, proposing an approach for delineating different salinity and sodicity zones was the third objective. The study was carried out in 871.1 ha farmland in Southeast of Dushak town of Ahal Province, Turkmenistan. Soil properties, including electrical conductivity (EC), soil reaction (pH), sodium adsorption ratio (SAR), calcium carbonate and particle size distribution (clay, silt and sand fractions) in 0–30, 30–60, 60–90 and 90–120 cm soil layers were recorded. The EC values in different soil layers indicated serious soil salinization problem in the study area. The mean EC values in 0–90 cm depth were high (8 dS m-1), classifying the soils as moderate to strongly saline. Spatial dependence calculated by the nugget to sill ratio indicated a strong spatial autocorrelation. The elevation was the primary factor affecting spatial variation of soil salinity in the study area. The reclamation of the field can be planned based on three distinct areas, i.e., high (≥12 dS m-1), moderate (12–8 dS m-1) and low (<8 dS m-1) EC values. The spatial trend analyses of SAR values revealed similar patterns for EC and pH; both of which gradually decreased from north to the south-west. The amount of water needed to leach down the salts from 60 cm of soil profile is between 56.4–150.0 ton ha-1 and the average leaching water was 89.8 tons ha-1. The application of leaching water based on the amount of average leaching water will result in higher or lower leaching water application to most locations and the efficiency of the reclamation efforts will be low. Similar results were recorded for sulfur, sulfuric acid and gypsum requirements to remediate sodicity. The results concluded that the best management strategy in planning land development and reclamation schemes for saline and sodic soils require accurate information about the spatial distribution of salinity and sodicity across the target area.

Classification and Mitigation of Soil Salinization

2017 ◽  
Author(s):  
Tibor Tóth
Keyword(s):  
Soil Salinity ◽  
Soil Classification ◽  
Soil Salinization ◽  
Classification Systems ◽  
Salt Accumulation ◽  
Soil Taxonomy ◽  
Sodic Soils ◽  
Water Rates ◽  
Irrigated Lands ◽  
The Right

Soil salinity has been causing problems for agriculturists for millennia, primarily in irrigated lands. The importance of salinity issues is increasing, since large areas are affected by irrigation-induced salt accumulation. A wide knowledge base has been collected to better understand the major processes of salt accumulation and choose the right method of mitigation. There are two major types of soil salinity that are distinguished because of different properties and mitigation requirements. The first is caused mostly by the large salt concentration and is called saline soil, typically corresponding to Solonchak soils. The second is caused mainly by the dominance of sodium in the soil solution or on the soil exchange complex. This latter type is called “sodic” soil, corresponding to Solonetz soils. Saline soils have homogeneous soil profiles with relatively good soil structure, and their appropriate mitigation measure is leaching. Naturally sodic soils have markedly different horizons and unfavorable physical properties, such as low permeability, swelling, plasticity when wet, and hardness when dry, and their limitation for agriculture is mitigated typically by applying gypsum. Salinity and sodicity need to be chemically quantified before deciding on the proper management strategy. The most complex management and mitigation of salinized irrigated lands involves modern engineering including calculations of irrigation water rates and reclamation materials, provisions for drainage, and drainage disposal. Mapping-oriented soil classification was developed for naturally saline and sodic soils and inherited the first soil categories introduced more than a century ago, such as Solonchak and Solonetz in most of the total of 24 soil classification systems used currently. USDA Soil Taxonomy is one exception, which uses names composed of formative elements.

scholarly journals Assessing the impact of shallow subsurface pipe drainage on soil salinity and crop yield in arid zone

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12622
Author(s):  
Haichang Yang ◽  
Weiye Chen ◽  
Yun Chen ◽  
Fenghua Zhang ◽  
Xiaohu Yang
Keyword(s):  
Crop Yield ◽  
Soil Salinity ◽  
Drip Irrigation ◽  
Soil Salinization ◽  
Water Salinity ◽  
Growth Stages ◽  
Plastic Mulch ◽  
Soil Layers ◽  
Shallow Subsurface ◽  
The Impact

Purpose Soil salinization is one of the key problems of sustainable development of arid agricultural land. Exploring the use of shallow subsurface pipe drainage to improve soil salinization. Methods This study investigates the desalinization effect of shallow subsurface pipe drainage, in combination with drip irrigation under plastic mulch, in an arid region in China. Field data collection was conducted in 2010. Soil salinity at a range of soil depths, water EC and pH of subsurface pipe drainage and crop yield during crop growth stages in salinized farmlands were measured. Results and Conclusion The results show that soil salinity was reduced significantly on mildly (1–3 dS m−1) and moderately (3–6 dS m−1) salinized farmlands. The highest desalinization rate of mildly and moderately salinized soils was 51% and 91% respectively. The desalinization in upper soil layers, to a depth of 60 cm, was more significant than that in lower soil layers. Drainage water salinity was much higher than irrigation water salinity. Crop yield on mildly and moderately salinized land increased about 25% and 50%, respectively. This indicates that the combination of drip irrigation and shallow subsurface pipe drainage on farmlands is potential feasible to desalt farmlands and to improve crop yield. The study has led to a desalinization of 330 ha year−1 in Xinjiang.

Spatio-temporal variability of global soil salinization delineated by advanced machine learning algorithms

2020 ◽  
Author(s):  
Amirhossein Hassani ◽  
Adisa Azapagic ◽  
Nima Shokri
Keyword(s):  
Soil Salinity ◽  
Anthropogenic Activities ◽  
Soil Surface ◽  
Temporal Variations ◽  
Soil Salinization ◽  
Machine Learning Algorithms ◽  
Accurate Estimation ◽  
Quantitative Methodology ◽  
Sodic Soils ◽  
Spatio Temporal

&lt;p&gt;Soil salinity is among the major threats affecting the soil fertility, stability and vegetation. It can also accelerate the desertification processes, especially in arid and semi-arid regions. An accurate estimation of the global extent and distribution of the salt-affected soils and their temporal variations is pivotal to our understanding of the salinity-induced land degradation processes and to design effective remediation strategies. In this study, using legacy soil profiles data and a broad set of climatic, topographic, and remotely sensed soil surface and vegetative data, we trained ensembles of classification and regression trees to map the spatio-temporal variation of the soil salinity and sodicity (exchangeable sodium percentage) at the global scale from 1980 to 2018 at a 1 km resolution. The User&amp;#8217;s Accuracies for soil salinity and sodicity classification were 88.05% and 84.65%, respectively. The 2018 map shows that globally &amp;#160;&amp;#820; 944 Mha of the lands are saline (with saturated paste electrical conductivity &gt; 4 ds m&lt;sup&gt;-1&lt;/sup&gt;), while &amp;#160;&amp;#820; 155 Mha can be classified as sodic soils (with sodium exchange percentage &gt; 15%). Our findings and provided dataset show quantitatively how soil salinization is influenced by a broad array of climatic, anthropogenic and hydrologic parameters. Such information is crucial for effective water and land-use management, which is important for maintaining food security in face of future climatic uncertainties. Moreover, our results combined with the quantitative methodology developed in this study will provide us with an opportunity to delineate the role of anthropogenic activities on soil salinization. This information is useful not only for developing predictive models of primary and secondary soil salinization but also for natural resources management and policy makers.&lt;/p&gt;

scholarly journals Evaluation of salinization and sodification in irrigated areas with limited soil data: Case study in southern Portugal

2018 ◽  
Vol 8 ◽  
Author(s):  
Carlos Alexandre ◽  
Teresa Borralho ◽  
Anabela Durão
Keyword(s):  
Soil Salinity ◽  
Irrigation Water ◽  
Soil Salinization ◽  
Soil Survey ◽  
Water Salinity ◽  
Irrigated Agriculture ◽  
Sodic Soils ◽  
Irrigated Area ◽  
Southern Portugal

Due to its high land productivity, irrigated agriculture has an increasing role in food production. In the Alentejo region (southern Portugal) the irrigated area has grown since the completion of the Alqueva dam in 2002. Climatic change patterns foreseen for the Mediterranean region (more heat extremes, less precipitation and river flow, increasing risk of droughts and decrease in crop yields) are prone to soil salinization and sodification in irrigated areas in the region. The Roxo dam has some of the higher records of water salinity and sodicity in Portugal, which makes the Roxo irrigated area (RIA) a very interesting case study. This paper aimed at two main objectives for the RIA: (i) evaluate soil salinization and sodification, and make spatial predictions of soils susceptibility to these degradation types; (ii) monitor current salinity and sodicity of the water, and simulate the effect of empirical based scenarios of water salinity and sodicity. The RIA (8250 ha) extends ~20 km along the Roxo river (northern Aljustrel), in Cenozoic sedimentary formations. Main soils mapped are: Luvisols (~40%), Fluvisols and Regosols (~20%), Gleysols and Planosols (~20%) and Vertisols (~10%). However, there are only five soil profiles with detailed analytical data from a more recent soil survey with 83 profile descriptions in the RIA and surrounding area. Irrigation water of the Roxo dam and drainage water of the Roxo river were monitored almost monthly during Jul/2014-Nov/2015 and Jun/2016-Jan/2017, for determination of electrical conductivity (EC), sodium adsorption ratio (SAR), and other parameters. Soil salinity was not a significant problem in the RIA but a potential abundance of sodic soils was found that need future confirmation. A qualitative soil salinity index applied to the RIA suggests that soils most susceptible to salinity occur to a much smaller extent when this index is obtained from the soil profile data (approach B) than when it is based on information of the soil map (approach A). During the monitoring periods, both the water of the Roxo dam and of the Roxo river were slight to moderate saline for crop growth, with no restrictions for soil infiltration. The Roxo dam received water from the Alqueva dam for the first time between June and September 2016, and a small, though regular, decrease of the water EC (0.99 to 0.76 dS m<sup>-1</sup>) was observed during the same period. Three scenarios of irrigation water, identified by Low/High EC-SAR (L-L, H-H, L-H) were simulated with the Watsuit model. Low EC water (L-L and L-H) represent wet years and show no risk of soil salinity in the rootzone. However, the risk of waterlogging increases in sodic soils, especially with the scenario (L-H). High EC water (H-H) represents dryer years and results in severe saline conditions in the rootzone. In all three scenarios, prosodic and sodic soils are most sensible to degradation by salinization, sodification or both.

scholarly journals Linking Long-Term Changes in Soil Salinity to Paddy Land Abandonment in Jaffna Peninsula, Sri Lanka

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 211
Author(s):  
Tharani Gopalakrishnan ◽  
Lalit Kumar
Keyword(s):  
Sri Lanka ◽  
Soil Salinity ◽  
Agricultural Land ◽  
Sea Water ◽  
Land Use Changes ◽  
Soil Salinization ◽  
Landsat Images ◽  
Paddy Land ◽  
Semi Arid Region

Soil salinity is a serious threat to coastal agriculture and has resulted in a significant reduction in agricultural output in many regions. Jaffna Peninsula, a semi-arid region located in the northern-most part of Sri Lanka, is also a victim of the adverse effects of coastal salinity. This study investigated long-term soil salinity changes and their link with agricultural land use changes, especially paddy land. Two Landsat images from 1988 and 2019 were used to map soil salinity distribution and changes. Another set of images was analyzed at four temporal periods to map abandoned paddy lands. A comparison of changes in soil salinity with abandoned paddy lands showed that abandoned paddy lands had significantly higher salinity than active paddy lands, confirming that increasing salts owing to the high levels of sea water intrusion in the soils, as well as higher water salinity in wells used for irrigation, could be the major drivers of degradation of paddy lands. The results also showed that there was a dramatic increase in soil salinity (1.4-fold) in the coastal lowlands of Jaffna Peninsula. 64.6% of the salinity-affected land was identified as being in the extreme saline category. In addition to reducing net arable lands, soil salinization has serious implications for food security and the livelihoods of farmers, potentially impacting the regional and national economy.

scholarly journals The soil-adjusted vegetation index for soil salinity assessment in Uzbekistan

2020 ◽  
Vol 26 (3) ◽  
pp. 324-333
Author(s):  
Nozimjon Teshaev ◽  
Bunyod Mamadaliyev ◽  
Azamjon Ibragimov ◽  
Sayidjakhon Khasanov
Keyword(s):  
Soil Salinity ◽  
Information Technologies ◽  
Vegetation Index ◽  
Arable Land ◽  
Salt Content ◽  
Secondary Data ◽  
Soil Surface ◽  
Soil Salinization ◽  
Arid Zones ◽  
Agronomic Practices

Soil salinization, as one of the threats of land degradation, is the main environmental issue in Uzbekistan due to its aridic climate. One of the most vulnerable areas to soil salinization is Sirdarya province in Uzbekistan. The main human-induced causes of soil salinization are the insufficient operation of drainage and irrigation systems, irregular observations of the agronomic practices, and non-efficient on-farm water use. All of these causes considerably interact with the level of the groundwater, leading to an increase in the level of soil salinity. The availability of historical data on actual soil salinity in agricultural lands helps in formulating validated generic state-of-the-art approaches to control and monitor soil salinization by remote sensing and geo-information technologies. In this paper, we hypothesized that the Soil-Adjusted Vegetation Index-based results in soil salinity assessment give statistically valid illustrations and salinity patterns. As a study area, the Mirzaabad district was taken to monitor soil salinization processes since it is the most susceptible territory of Sirdarya province to soil salinization and provides considerably less agricultural products. We mainly formulated this paper based on the secondary data, as we downloaded satellite images and conducted an experiment against the in-situ method of soil salinity assessment using the Soil-Adjusted Vegetation Index. As a result, highly saline areas decreased by a factor of two during the studied period (2005–2014), while non-saline areas increased remarkably from a negligible value to over 10 000 ha. Our study showed that arable land suitability for agricultural purposes has been improving year by year, and our research held on this district also proved that there was a gradual decrease in high salt contents on the soil surface and land quality has been improved. The methodology has proven to be statistically valid and significant to be applied to other arid zones for the assessment of soil salinity. We assume that our methodology is surely considered as a possible vegetation index to evaluate salt content in arable land of either Uzbekistan or other aridic zones and our hypothesis is not rejected by this research.

scholarly journals Saline-sodic soil treated with gypsum, organic sources and leaching for successive cultivation of sunflower and rice

2019 ◽  
Vol 23 (12) ◽  
pp. 891-898 ◽  
Author(s):  
Petrônio D. dos Santos ◽  
Lourival F. Cavalcante ◽  
Hans R. Gheyi ◽  
Geovani S. de Lima ◽  
Everaldo M. Gomes ◽  
...  
Keyword(s):  
Surface Layer ◽  
Rice Husk ◽  
Rice Variety ◽  
Rice Cultivation ◽  
Exchangeable Sodium ◽  
Sodic Soils ◽  
Sodic Soil ◽  
Soil Layers ◽  
Before And After ◽  
Irrigated Perimeter

ABSTRACT Correction of saline and sodic soils aims to reduce salts dissolved in the solution and exchangeable sodium, respectively, to allow the growth and production of crops. In this context, an experiment was carried out between August/2011 and September/2012, in saline-sodic soil of the Irrigated Perimeter of São Gonçalo, in the municipality of Sousa, PB, Brazil. Agricultural gypsum, organic sources and continuous leaching for reducing salinity, sodicity and alkalinity in the saline-sodic soil and their effects on the production of the sunflower cultivar Embrapa 122/V-2000 and the rice variety Diamante were evaluated. The treatments were distributed in four randomized blocks and the soil was subjected to continuous leaching for 50 days and evaluated for salinity, sodicity and alkalinity before and after leaching, as well after sunflower and rice cultivation, in the 0-0.20 and 0.20-0.40 m layers. Leaching and the application of gypsum and organic sources reduced the initial salinity in both soil layers, to a greater extent in the surface layer. Exchangeable sodium decreased in 0-0.20 m and increased in 0.20-0.40 m. After rice cultivation, the soil in the 0-0.20 m layer changed from saline-sodic to non-saline in the treatments gypsum + bovine manure and gypsum + rice husk. The reduction of salinity, sodicity and alkalinity in the soil was higher during rice cultivation than during sunflower cultivation.

scholarly journals Soil salinization under different climate change scenarios: A global scale analysis

2021 ◽  
Author(s):  
Nima Shokri ◽  
Amirhossein Hassani ◽  
Adisa Azapagic
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Soil Salinity ◽  
Global Scale ◽  
Soil Salinization ◽  
Water Evaporation ◽  
Climate Change Scenarios ◽  
Spatio Temporal ◽  
Salt Affected Soils

&lt;p&gt;Population growth and climate change is projected to increase the pressure on land and water resources, especially in arid and semi-arid regions. This pressure is expected to affect all driving mechanisms of soil salinization comprising alteration in soil hydrological balance, sea salt intrusion, wet/dry deposition of wind-born saline aerosols &amp;#8212; leading to an increase in soil salinity. Soil salinity influences soil stability, bio-diversity, ecosystem functioning and soil water evaporation (1). It can be a long-term threat to agricultural activities and food security. To devise sustainable action plan investments and policy interventions, it is crucial to know when and where salt-affected soils occur. However, current estimates on spatio-temporal variability of salt-affected soils are majorly localized and future projections in response to climate change are rare. Using Machine Learning (ML) algorithms, we related the available measured soil salinity values (represented by electrical conductivity of the saturated paste soil extract, EC&lt;sub&gt;e&lt;/sub&gt;) to some environmental information (or predictors including outputs of Global Circulation Models, soil, crop, topographic, climatic, vegetative, and landscape properties of the sampling locations) to develop a set of data-driven predictive tools to enable the spatio-temporal predictions of soil salinity. The outputs of these tools helped us to estimate the extent and severity of the soil salinity under current and future climatic patterns at different geographical levels and identify the salinization hotspots by the end of the 21&lt;sup&gt;st&lt;/sup&gt; century in response to climate change. Our analysis suggests that a soil area of 11.73 Mkm&lt;sup&gt;2&lt;/sup&gt; located in non-frigid zones has been salt-affected in at least three-fourths of the 1980 - 2018 period (2). At the country level, Brazil, Peru, Sudan, Colombia, and Namibia were estimated to have the highest rates of annual increase in the total area of soils with an EC&lt;sub&gt;e&lt;/sub&gt; &amp;#8805; 4 dS m&lt;sup&gt;-1&lt;/sup&gt;. Additionally, the results indicate that by the end of the 21&lt;sup&gt;st&lt;/sup&gt; century, drylands of South America, southern and Western Australia, Mexico, southwest United States, and South Africa will be the salinization hotspots (compared to the 1961 - 1990 period). The results of this study could inform decision-making and contribute to attaining the United Nation&amp;#8217;s Sustainable Development Goals for land and water resources management.&lt;/p&gt;&lt;p&gt;1. Shokri-Kuehni, S.M.S., Raaijmakers, B., Kurz, T., Or, D., Helmig, R., Shokri, N. (2020). Water Table Depth and Soil Salinization: From Pore-Scale Processes to Field-Scale Responses. Water Resour. Res., 56, e2019WR026707. https://doi.org/ 10.1029/2019WR026707&lt;/p&gt;&lt;p&gt;2. Hassani, A., Azapagic, A., Shokri, N. (2020). Predicting Long-term Dynamics of Soil Salinity and Sodicity on a Global Scale, Proc. Nat. Acad. Sci., 117, 52, 33017&amp;#8211;33027. https://doi.org/10.1073/pnas.2013771117&lt;/p&gt;

scholarly journals On the issue of chemical mechanism and soil salinity degree determination: Russian and foreign practices

2021 ◽  
Author(s):  
S. A. Manzhina ◽  
Keyword(s):  
Retrospective Analysis ◽  
Soil Salinity ◽  
Soil Degradation ◽  
Soil Salinization ◽  
Individual Characteristics ◽  
Chemical Mechanism ◽  
International Level ◽  
Salt Composition ◽  
Soil Salt

Purpose: analysis of the currently available approaches to determining the chemical mechanism and degree of soil salinity. In the course of research, the researches of Russian and foreign scientists, Russian and foreign methodological documents in the field of determining the degree and type of land salinization were studied. The methods of data analysis, processing and generalization were used. Discussion. The retrospective analysis of the Russian and foreign practices of assessing the degree and types of soil salt degradation was made by the author. The main indicators, assessed in the process of determining the degree and chemistry of soil salinization, as well as the methods for their determination, generally accepted in Russia and abroad, are given. Identification of these characteristics is of great importance in planning and carrying out reclamation activities aimed at increasing soil fertility, preventing soil degradation and loss of agricultural and commercial value. Conclusions. Based on a retrospective analysis of various possibilities for determining and classification of soil salt degradation, it was concluded that there are various methods oriented both to individual characteristics of soils in order to identify their unfavorable salt composition, and to different approaches to the procedures and methods of diagnosis. The main purpose of identifying the salt imbalance in agricultural lands composition is the possibility of preserving and improving their fertility, which, undoubtedly is carried out through reclamation measures in the case of their degradation. In order to develop uniformity in assessment and interpretation of data on the salt composition of soils, the degree of their salinity and the need for one or another type of reclamation work, it is necessary to develop a system of indicators based on the experience of Russian and foreign scientists with international practices. The development of the specified regulatory and methodological documentation should be focused on the international level, take into account all possible indicators affecting the accuracy of determination, excluding unnecessary details.

Revealing the spatial pattern of subsurface soil salinity over the Argentinean Dry Chaco

2021 ◽  
Author(s):  
Michiel Maertens ◽  
Veerle Vanacker ◽  
Gabriëlle De Lannoy ◽  
Frederike Vincent ◽  
Raul Giménez ◽  
...  
Keyword(s):  
Soil Salinity ◽  
Land Surface ◽  
Large Scale ◽  
Hydrological Cycle ◽  
Regional Scale ◽  
Shallow Groundwater ◽  
Soil Salinization ◽  
Dry Forest ◽  
Surface Model ◽  
Subsurface Soil

&lt;p&gt;The South-American Dry Chaco is a unique ecoregion as it is one of the largest sedimentary plains in the world hosting the planet&amp;#8217;s largest dry forest. The 787.000 km&amp;#178; region covers parts of Argentina, Paraguay, and Bolivia and is characterized by a negative climatic water balance as a consequence of limited rainfall inputs (800 mm/year) and high temperatures (21&amp;#176;C). In combination with the region&amp;#8217;s extreme flat topography (slopes &lt; 0.1%) and shallow groundwater tables, saline soils are expected in substantial parts of the region. In addition, it is expected that large-scale deforestation processes disrupt the hydrological cycle resulting in rising groundwater tables and further increase the risk for soil salinization.&lt;/p&gt;&lt;p&gt;In this study, we identified the regional-scale patterns of subsurface soil salinity in the Dry Chaco. &amp;#160;Field data were obtained during a two-month field campaign in the dry season of 2019. A total of 492 surface- and 142 subsurface-samples were collected along East-West transects to determine soil electric conductivity, pH, bulk density and humidity. Spatial regression techniques were used to reveal the topographic and ecohydrological variables that are associated with subsurface soil salinity over the Dry Chaco. The hydrological information was obtained from a state-of-the-art land surface model with an improved set of satellite-derived vegetation and land cover parameters.&lt;/p&gt;&lt;p&gt;In the presentation, we will present a subsurface soil salinity map for a part of the Argentinean Dry Chaco and provide relevant insights into the driving mechanisms behind it.&lt;/p&gt;

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